Sample for TriSlice Component Plugin

This sample project showcases the TriSlice Component.

The TriSlice Component plugin introduces a 3D slicing technique known as 27 Slicing to Unreal Engine. This method enables dynamic, non-uniform scaling of 3D meshes while preserving artistic fidelity, analogous to 9-slicing in 2D textures. By dividing a 3D mesh into 27 regions, this component provides efficient scaling and deformation with minimal distortion, preserving the geometry of key areas like corners, edges, and the center.

Features

• 27 Slicing for 3D Meshes: Scale and deform meshes dynamically while preserving critical details.
• Precise Slice Borders: Define regions of the mesh (corners, edges, faces, center) with normalized slice borders for each axis.
• Customizable Scaling Behavior: Control whether the center region stretches or remains fixed during scaling.
• Pivot-Based Slicing: Adjust the slicing pivot for precise control of slice borders.
• Collision Mesh Generation: Automatically generate a collision mesh for the sliced geometry.
• Asynchronous Slicing: Perform slicing computations asynchronously for better performance.
• Mesh Scale Control: Use either the actor scale or a custom MeshScale property for slicing.

Installation

1. Clone or download this repository into your Unreal project’s Plugins folder.
2. Enable the plugin in the Plugins menu in Unreal Editor.
3. Restart the editor to complete the installation.

Getting Started

Adding the Component

1. Open your actor’s blueprint or C++ class.
2. Add the TriSlice Component as a child of your actor.
3. Assign a Static Mesh to the component's Mesh property.

   Note: Ensure that CPU Access is enabled for the assigned mesh:

   • Open the mesh asset in the editor.
   • Under Details → General Settings → Advanced, enable Allow CPU Access.

Configuring Slicing

The primary slicing behavior is defined by the following properties:

• Slice Borders:

  • BorderXNegative, BorderXPositive
  • BorderYNegative, BorderYPositive
  • BorderZNegative, BorderZPositive
    These normalized values (0.0–1.0) define where the mesh is divided along each axis. If the border is set to 1.0, the mesh will stretch on that side as it normally does when scaling. If the border is set to 0.8, only the inner 80% will stretch, while the outer 20% remains fixed.

• Pivot Adjustment:

  • Use the SlicerPivotOffset property to fine-tune the slicing pivot if it differs from the mesh’s center.

• Center Scaling:

  • Use the ScaleCenterMode property to determine whether the center region stretches during scaling. This is particularly useful for preserving key features like engravings or functional elements. See the sample for a visual example.

Triggering Slicing

• Automatic Slicing: Slicing occurs automatically when:
  • The game starts.
  • The owning actor’s scale changes.
• Manual Slicing: Call the SliceMesh method to trigger slicing manually.

Debugging Slicing

Enable debug properties to visualize slicing behavior in the editor:

• bDebugDrawPivot: Display the slicing pivot.
• bDebugDrawBorderX, bDebugDrawBorderY, bDebugDrawBorderZ: Display slice borders for each axis.

Collision and Performance

• Collision Mesh: Enable or disable collision mesh generation using the bGenerateCollision property.
• Asynchronous Slicing: Improve performance by enabling bAsyncSlice (enabled by default).

Using Custom Mesh Scale

If you do not want to scale the actor itself:

1. Set bUseActorScale to false.
2. Use the MeshScale property to define the mesh scale directly.

Documentation

For detailed information on the available properties and methods of the TriSlice Component, refer to the API documentation provided in the source code.

Known Issues

• Textures may stretch in the center region if not designed for scaling. Adding additional loop cuts may mitigate this issue.
• Ensure CPU access is enabled for the mesh, or slicing will not function.